title: Small nerve fiber pathology in critical illness.
abstract: BACKGROUND
  Degeneration of intraepidermal nerve fibers (IENF) is a hallmark of small fiber neuropathy of different etiology, whose clinical picture is dominated by neuropathic pain. It is unknown if critical illness can affect IENF.
  
  
  METHODS
  We enrolled 14 adult neurocritical care patients with prolonged intensive care unit (ICU) stay and artificial ventilation (≥ 3 days), and no previous history or risk factors for neuromuscular disease. All patients underwent neurological examination including evaluation of consciousness, sensory functions, muscle strength, nerve conduction study and needle electromyography, autonomic dysfunction using the finger wrinkling test, and skin biopsy for quantification of IENF and sweat gland innervation density during ICU stay and at follow-up visit. Development of infection, sepsis and multiple organ failure was recorded throughout the ICU stay.
  
  
  RESULTS
  Of the 14 patients recruited, 13 (93%) had infections, sepsis or multiple organ failure. All had severe and non-length dependent loss of IENF. Sweat gland innervation was reduced in all except one patient. Of the 7 patients available for follow-up visit, three complained of diffuse sensory loss and burning pain, and another three showed clinical dysautonomia.
  
  
  CONCLUSIONS
  Small fiber pathology can develop in the acute phase of critical illness and may explain chronic sensory impairment and pain in neurocritical care survivors. Its impact on long term disability warrants further studies involving also non-neurologic critical care patients.
authors.affiliation: Department of Anesthesia and Critical Care Medicine, Section of Neuroanesthesia and Neurocritical Care, University of Brescia at Spedali Civili, Brescia, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Latronico
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Filosto
authors.forename: Nazzareno
authors.initials: N
authors.lastname: Fagoni
authors.forename: Laura
authors.initials: L
authors.lastname: Gheza
authors.forename: Bruno
authors.initials: B
authors.lastname: Guarneri
authors.forename: Alice
authors.initials: A
authors.lastname: Todeschini
authors.forename: Raffaella
authors.initials: R
authors.lastname: Lombardi
authors.forename: Alessandro
authors.initials: A
authors.lastname: Padovani
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lauria
mesh_terms: D000328:Adult; D001706:Biopsy; D004576:Electromyography; D000078404:Epidermal Cells; D004916:Erythromelalgia / Q000503:physiopathology*; D006801:Humans; D007150:Immunohistochemistry; D007362:Intensive Care Units; D007558:Italy; D009410:Nerve Degeneration / Q000503:physiopathology*; D009412:Nerve Fibers / Q000473:pathology*; D009431:Neural Conduction / Q000502:physiology; D013545:Sweat Glands / Q000294:innervation